Baking oven



' Feb. s, 1940.

J. V. COOK 13111111111` OVEN Filevd March 26, 1938 2 Sheet's-Shet 1 Y IZ-mm: u Yo-Nd /G a ab Patented Feb. r6, 1940 UNITED STATES PATENT OFFICE BAKING OVEN poration oi' Illinois Application March 26, 1938, Serial No. 198,295

12 Claims.

Myinvention relates to baking ovens and ithas for its object the provision of a new and improved form and arrangement o1' parts in a device of this type whereby the heat may be distributed more eifenly vand more effectively throughout the baking chamber transversely thereof. To this end, it is one of the objects of my invention to provide an improved system of vanes and dampers for regulating the delivery m of heat to a series of ilues by which the heat is distributed through the oven. It is another object also to provide a single zone oven having only space enough between its top and bottom walls to accommodate an endless conveyor having 35 its top and bottom leads each located in substantially horizontal position from one end of the baking chamberv to the other, the arrangement being such as to provide homogeneous air and steam conditionsI throughout the chamber.

It is one of the objects of my invention to pro- I vide an improved circulating heat arrangement by which heated gases are passed a plurality of times through the ues so as to get the maximum benefit therefromand in which the major por-v tion of the stream of such heated gases after being cooled more or less by its passage through the iues is drawn through a mixing chamber where it is blended with a vcomparatively much smaller supply of fresh highly heated gases which is 3o thereby brought -down to the desired working temperature so as to avoid burning out the working parts` 4It is another object of my invention to provide an improved arrangement of mixing chamber and associated p'arts whereby the 35 mingling of the two. components of the gases to make up the heating stream may be effected thoroughly and expeditiously for securing the desired even application of the heat throughout the oven. It is another object of my invention to provide an improved arrangement of this type of such construction that the heating may be effected with a' minimum loss of heat so as to cut down the costof `the heating operation to a minimum while at the same time sufllcient fresh air shall be introduced for supporting combustion eifectively ingconnectionl with a burner of any lapproved type.

It is another object o! my invention to provide anI improved arrangement whereby greatly im- 5o 'proved results may be attained with respect tov the expansion and contractionof the oven parts Y `as the temperature of the oven is raised tor a baking operation and vis then permitted to fall between v'periods of use of the oven and whereby the uneven expansion of 'parts located adjacent to' (ci 1oz-ss) each other may be effected with a minimum tendency for the change in size or shape of one part to cause an adjacent part also to be warped or distorted or to -be placed under heavytension. It is another object of my invention to improve 5 4baking ovens in sundry details hereinafter point# ed out. 'I'he preferred means by which I -have accomplished my'several objects are illustrated in the drawings and are hereinafter specifically described. 'Ihat which I believe to be new and 10 desire to cover by Letters IPatentis set forth in the claims. l

In the drawings, all of which are more or less diagrammatic- Fig. 1 is a longitudinal vertical sectional view l5 through the preferred form of my improved oven, being'takensubstantially at line I-I of Fig. 2; A

Fig. 2 isa horizontal sectional view taken substantially at line 2-2 fof Fig. 1;

Fig. 3 is a vertical sectional view through my 20 improved oven, being taken substantially at the lines 3'3 in Figs. 1 and 2; E

Fig. 4` is a horizontal sectional view taken on an enlarged scale at line 4 4 of Fig. 1; and

Fig. \5 is a vertical sectional view taken at line 25 l 5-5 of Fig. 4.

Referring now to the several figures of the drawings, in whichcorresponding parts are indicated by the same reference characters, I2 in' dicates an outside housing formedpreferably' of 3'0 sheetmetal supported and reinforced by any approved type of framework not shown. Within the outside housing I2, I have provided a baking chamber unit I3 also having sheet metal wall portions comprising side walls I4 ad I5 as shown 35 in Fig. 4 and cooperating wallportionsof any approved type. Between the walls of the housing( l2 and the walls of the baking chamber Aunit I3,

I have provided heat insulation material I6. of f any approved type by which the oven is ef- 40 fectively insulated against undue loss of heat from the baking chamber.

Atthe forward end of the oven, the baking chamber is closed by a door I 'I of any approved type, a removable panel I8," and a depending 45 iixed panel portion I 9 above the door. In the ar'. rangement shown, the depending panel portion I9 and the removable panel I8 are formed of sheet metal having walls in spaced relation and having insulation I6 therein. In the arrange.- 50 ment shown, the door-I1 is slidable upwardly being supported by cables 20 at opposite sides of the oven running over sheaves'2l and provided at. their lower ends with a -counterweight -22 underneath the baking oven as isshown in Figli for 55 A facilitating the opening and closing movements of said door. Y

As is best shown in'Fig. 1, a hood structure 23 is provided over vthe upper edge of the door I1,

connected at its upper face with a stack 24 in position'to receive and carry away any heated gases escaping between the door I1 and the adjacent walls, being effective when the door is opened to control the escaping hot air so as to make it safe fo'r an operator to work adjacent to the front end of the oven.

Within -the baking chamber, I have mounted an endless conveyor of any approved type operating between sprocketgears 25 and 26, which are shown only diagrammatically since they form in and of themselves no part of my present invention. -In the arrangement shown, the sprockets 25 are held resiliently in position by means of springs 21 which are adapted to keep the conveyor at the desired operating tension s expansion takes place during the time when the oven is being heated ready for use. This conveyor, indicated'generally by the numeral 28, is made of metal having substantially-the same coeflicient of expansion as that of the sidewalls I4 and I5 so that the springs 21 are maintained at substantially unform tension during' and contraction of the parts. l

Within the baking chamber, I have mounted a header 29 formed of sheet metal and being' located at an intermediate point lengthwise of the oven. At its forward face, the' header 29 has a series of ilues 30 connected therewith, such flues being in spaced relation with respect to each other throughout substantially the full width of the baking chamber and the oven as vshown in Figs. 2 and 4. 'I'he flues 30, which in the arrangement shown are in the form of metal pipes are connectedat their forward ends to a header 3| also formed of sheet metal and extending transversely of the oven parallel with the header 29. The header -3I is supported by means of plates 32 (see Fig. 3) which are slidably mounted at opposite ends of an I-beam 33 extending transversely of the oven and supported'in position by any suitable connection with the framework of the housing I2. In the construction illustrated, the ilues' 30 have a rigid connection with the header 3|, preferably by means oi screw threads, while at their opposite ends such iiues have a. slip joint connection with the headerg29wsuch slip joint connection being effected by the use of short sleeves 34 connected with the header and receiving the rear ends ofthe flues 39 .sli bly therein,4 as is best shown in Fig. 5. At the op site end of the oven, I have provided a vthird header 35 also formed of sheet metal, being connected with the header 3|- by means of a series of ues 36 which in the arrangement shown have a rigid connection with both of said headers. In the arrangement shown, the iiues 36, generally speaking, are in staggered relation horizontally with respect toilues 36 shall differ slightly from that of the ues 30, such ilues are adapted to slide to the necessary extent with respect to the header 29 so as to prevent any tendency for a distortion of any of the parts. Y By reason of my improved ar- 5 rangement comprising the diiferential connection of the iiues to the headers, the expansion of the parts is permitted without the application of any expansion .is best shown in Fig. 1.

the fiues 30, as is clearly shown in Figs. 2 and 3,

70 wardly and backwardly with respect to the I-beam .1' 33, such header 3| is free to move longitudinally of the-oven with lrespect to the adjacent parts as may be necessary by reason of uneven expansion of the flues with respect to the expansion of 15.: parts. In case the expansion of the v great stress on the parts for warping them or otherwise, whereby the wear and tear on the l0 structure is very greatly reduced as compared with that in connection with rigid structures such as have been employed heretofore.

In my improved construction, the header 3| is preferably* formed of two parts comprising a 15 plate portion 31 which has a rigid connection with the flues and a dished portion 38 which is removably mounted for providing access to the ues when desired. When access to the iiues is desiredg' the door or panel I8 can be removed for 20 such purpose. As is clearly shown in Figs. 2 and 3, the header 3| is provided' withy partitions 39,

40 and 4| at spaced intervals therealong so as to divide the ilues into four sets for assuring that the heated gases going forward through the ues 25 30 of one set shall return through the ues 36 of the same set.

The means in the construction illustrated for producing the required heat and forcing it through the flues 30 and 36 comprises a mixing 80 chamber 42 which in the arrangement shown is cylindrical in vform extending from one side of the furnace to about the middle of the furnace 'transversely thereof, such chamber opening at sprockets 41 `and 49 with the drive shaft of an 40 electric motor 49, the shaft 45 being journaled in suitable bearings mounted rigidly in position. The arrangement is such that the air or other gases taken by the pump 43 from the mixing chamber 42 are delivered through the duct 441 4g and header 29 to the flues 30 and thence through the header 3| and fiues 36 t'o the header 35 from which such gases are adapted to pass again to the mixing chamber 42 through a duct 5| opening from the header 35 at one side of the furnace g@ as is best shown in Fig. 2. I

In the arrangement shown, a stack 52 rises from the housing I2 at its rear end portion, communicating at its lower end with a conduit 53 which opens at its lower endinto the duct 5I, as 5;.;

Bythis arrangement, the stack 52 is adapted to apply suction upon the header 35 in opposition to that applied through the action of the pump or blower 43. For controlling the proportion of the air and other gases passing out through the stack 52 as compared with those recirculating through the iiues 30 and 35, I have provided a pivotally mounted damper 54 at the point where the conduit 53 opens. into the duct 5|. By a proper -adjustment of the g5 damper 54 about its horizontal axis the proportion'of the gases escaping through the stack as comparedwith those passing again through the nues 30 and 36 can be controlled. Any suitable means maybe provided as desired for locking the damper 54 in the desired adjusted position. i The stack 52 is preferably prvovided with a damper 55 of any suitable pe operated by a handle 56 fory controlling the escape of heat through the stack.

In the arrangement shown, the means for pro- '15 ducing heat within thefurnace comprises a tubular member 51 formed of a good quality of lre clay having itsfwalls in spacedrelation to the walls of the mixing chamber 42, as is best shown in Figs. 1 and 4, suchl tubular member being open at its inner end directly into the mixing chamber. At its outer end, the tubular member 51 is provided with an opening 58 therefrom through which the nozzle 59 of an oil burner is to be inserted for the introduction of a combultible mixture of vaporized oil and air for com-` bustion within the tubular member 51, as will be readily understood. i

As is best shown in Fig. 1, the duct 5| opening from the header 35 to the mixing chamber 42` is located at one side of the mixing chamber so as to direct the gases through the duct 5l tangentially with respect to the combustion chamber member 51 so as to cause the air to swirl about the tubular member soas to insure a thorough blending of the partially cooled gases-from the header 35 with the highly heated smaller supply ofV gases emerging from the end of the combustion chamber member 51. At one side of the mixing chamber 42, I have provided a blowout pad 60 of any suitable type which is readily removable from 4position in case greatly excessive pressure should develop within such chamber.

For insuring the desired even distribution of the heated gases to the several flues 30 and 36l spaced transversely of the oven, I have provided in the header 29 a plurality of vanes 5| having their rear edges. located opposite the forward end of the duct 44, such vanes being in forwardly divergent position with respect to each other so as to provide forwardlydivergent paths for the heated gases entering the header lfrom the duct 44. In connection with such vanes, I have provided three dampers 62 pivotally mounted upon vertical axes opposite the rear edges of the intermediate vanes 6|, such dampers being in the form of blades which are adapted to swing toward and from each other about their pivotal axes. As will be readily understood, by an adjustment of such blades 52 transversely with respect to each other, theproportions of the heated gases entering the header through the duct 44 can be regulated as desired. In the arrangement shown, the blades 62 are mounted upon pivot pins 63 which extend downwardly from the header 29 through the bottom wall of the housingl I2 so as to provide access to such pivot pinsl below the oven. Lock nuts` 64 are provided upon each of said pivot pins for locking the dampers in any desired adjusted position. l

I have found in practice that when the dampers 52 have been adjusted properly after the com-- plete installation of an oven and when the damper 54 has likewise been adjusted to its most effective position, the oven is in' condition for long continued effective operation without the neces.

sity for any further adjustment of these parts. I have found that with the dampers properly positioned the distribution of the heat throughoutl the baking chamber transversely thereof is very even as would ordinarily be desired and the escape of heat through the stack 52 is limited so as to correspond with the amount of fresh air re- 4quired for supporting combustion within the combustion chambermember 51.

While I prefer to employ the construction and arrangement as illustrated in my drawings and asabove described, it isl to be understood that my invention is not limited thereto except so far as the claims may be so limited, it being understood that changes might well be made in the form and arrangement of the parts without departing from my invention.

I claim:

1. In a baking oven, the combination of a horizontally positioned baking chamber of substantially uniform height and having a door at one end, heating ilues within and extending substantially ,the full length of the chamber in substantially horizontal position, and meansA including hanging trays for carrying products to be baked along a substantially horizontal path above said ilues and substantially from one end to the other of saidl chamber and then4 along a substantially horizontal path at a higher level again substantially from one end to the other of the chamber, the combined height of the hanging trays in the two paths being approximately equal to onehalf the distance from the tops of the ues to the top wall of the chamber and the spaces between the trays in the two paths, between the trays in the lower path and the flues and between the trays in the -upper path and the topV wall of the chamber being substantially equal.

2. In a bakingoven, the combination of a header mounted at one end of the baking chamber, va second header located at a lower level in spaced relation to the ends of the baking chamber, a third header located at the opposite end portion of the baking chamber and movable toward and from said first named two headers, a set of iiues connected between said rst and third headers. and a set of iiues of considerably shorter length connected between said second and third headers, one of said sets of ilues having a slip joint connection with at least one of said headers to compensate for uneven longitudinal expansion or contraction of said ilues or parts associated therewith.

3. In a baking oven, the combination of a header fixedly mounted at one end of the baking chamber, a second header tlxedly mounted at a lower level in 'spaced relation to the ends of the baking chamber, a third header slidably mounted at the opposite end portion of the baking chamber, a series of :dues rigidly connected with said first and third headers, and a second series of iiues of considerably shorter lengths connected rigidly with said third header and having slip joint connection with said second header to compensate for uneven longitudinal expansion or contraction of said ilues or parts associated therewith.

4. In ak baking oven, the Acombination of a header extending across the bottom of the baking chamber adjacent Aone end thereof, a second header extending across the baking chamber adjacent but at a higher level than the first header,

a series of iiues in said chamber extending from the first header and connected with said second header for delivering moderately heated gases to the second header, a transversely disposed mixing chamber below said second header at one side of the oven, means for drawing gases from said mixing chamber at its inner end and delivering them to the first header, a tubular member insaid mixing chamber in spaced relation thereto at the outer end portion oi the mixing chamber and opening into the mixing chamber' at anintermediate point therealong, and a duct'- leading from the outer end lportion of said second header to said mixing chamber tangentially of said `tubular member so as to cause gases entering the4 mixing chamber from said second header to have a swirling motion about said tubular -meniber for thoroughly blending with other heated gases emerging from the open end of said tubular member.

5. In a baking oven, the combination of a header extending across the baking chamber transversely thereof, a second header extending across said baking chamber at a higher level, a

series of flues for conducting heated gases from to at one end of the mixing chamber and opening thereinto at an intermediate point therealong,

a duct leading from said second header to said y mixing chamber tangentially of said tubular lao member, means comprising a pump for drawing gases from said mixing chamber and said second header and delivering the gases to said rst named header for passage through said flues,

other means communicating with said duct for diverting a portion of the gases from said second header, and a damper in said duct for varying the relative size of the opening from the duct to said mixing chamber as compared with the size of the opening ,from the duct to said second named means for diverting gases from said header. g

6. In a baking oven, the combination of two headers extending across the baking chamber transversely thereof, a series of flues connected with said headers in spaced relation to each other transversely of the oven for conducting heated gases from one header to the other for heating the baking chamber, a duct leading into one of said headers and of small width as compared with the width of the baking chamber, means for delivering a stream of heated gases to said header through said duct, and means in said duct and said connected header for splitting up said stream of gases and directing parts of the stream to the flues at different portions of the baking chamber transversely thereof for providing a substantially even distribution of the heat.

'7. In a baking oven, the combination of a header extending across the baking chamber transversely thereof at an intermediate point lengthwise of the oven, a second header extending across said baking chamber at one end portion of the oven and at a higher level than that of the rst named header, a series of flues connected with said headers and extending from said rst named header substantially to the end of the oven and thence back substantially the full length of the oven to said second header, said ilues being arranged in spaced relation to each other substantially entirely across the oven transversely thereof for conducting heated gases from said rst named header to said second header for heating the baking chamber, a duct leading into said rst named header at the opposite side thereof from that at which said ues are connected thereto and being comparatively narrow as compared with the width of the oven, means for delivering a stream of heated gases' to said .header through said duct, and means in said duct and said header for splitting up saidA stream of gases and directing parts of the stream to the iiues at different portions of the bakingv chamber transversely thereof for providing a substantially even distribution of the heat.

8. In a baking oven, the combination of two headers extending across the baking chamber -transversely thereof, a series of ues connected with said headers in spaced relation to each other transversely oi' lthe oven for conducting heated gases from one header to the other for heating the baking chamber, a duct leading into one of said headers and of small width as compared with the width of the baking chamber, means for delivering a stream of heated gases to said header through said duct, vanes in said iirst named header in spaced relation to each other opposite said duct and diverging with respect to each other from said duct for directing parts of the stream of heated gases to the iiues at diierent portions of the baking chamber transversely thereof and adjustable means in said duct in association with the several intermediate varies for splitting the stream of gases into parts of the desired relative proportions for delivery `to the several diverging paths between said vanes for providing a substantially even distribution of the heat. l

9. In abaking oven, the combination oftwo headers extending across the baking chamber transversely thereof, a series of ilues connected with said headers in spaced relation to each other transversely of the oven for conducting heated gases from one header to the other for heating the baking chamber, a duct leading into one of said headers and of small Width as compared with the width of the baking chamber, means for delivering a stream of heated gases to said header through said duct. vanes in said first named header in spaced relation to each other opposite said duct and diverging with respect to each other from said duct for directing parts of the stream of heated gases to the nues at diierent portions of the baking chamber transversely thereof, and dampers in said duct in association with the several intermediate vane's and each comprising a blade member adjustable toward and from' the adjacent blade means for splitting the stream of gases into parts of thel desired relative pro- 4between said vanes for providing a substantially even distribution of the heat.

10. In a baking oven, the combination of two headers extending across the baking chamber transversely thereof, a series of flues connected with said headers in spaced relation to each other transversely of the oven for conducting heated gases from one header to the other for heating the baking chamber, a duct leading into'one of said headers and of small width as compared with the width of the baking chamber, means for delivering a stream of heated gases to said header through said duct, vanes in said rst named header in spaced relation to each other opposite said duct and diverging with respect to each other from said duct for directing parts of the stream of heated gases to the flues at different portions of the baking chamber transversely thereof, dampers in said duct in association with the several intermediate vanes and each comprising a blade member pivotally mounted on a vertical axis, and means accessible from the exterior of the baking chamber for holding said blades in the desired angular relation to each other for splitting the stream of gases into parts of the desired relative proportions for delivery to the several diverging paths between said vanes 'for providing a substantially even distribution transversely of the oven, means for delivering 7l v ansehe? 5 heated gases through the several'iiues to said header for heatingthe b'aklng chamber, a second set of ues connected with saidheader and also in spaced relation to each other transversely of the oven for taking the heated gases from said header so as to assist in heating the baking chamber,4 and a plurality of partitions across said header in spaced relation to each other transversely of the oven for insuring that the gases entering said header through a flue ot said rst named set shall pass from the header to a flue of the second set having approximately the same location transversely of the oven.

12. In -a baking oven, the combination of a header extending across. the baking chamber transversely thereof, a set of ues connected With said header in spaced relation to each other transversely of the oven for conducting heated gases to said header for heating the baking oven,

a duct leading into said header and ofsmall width as compared with the width of the baking chamber, means for delivering a stream of heated gases to said header through said duct, means in said duct and said header for splitting up said stream of gases and directing parts of the stream to the iiues at diierent portions ofthe baking chamber transversely thereof, a second header ex tending' across the baking chamber transversely thereof and connected with said iiue's, a second v set of ues connected with said second header andfalso in spaced relation to each other transversely of the oven for taking the heated gases from said second header, and`a plurality of partitions across said second header in spaced relation to each other transversely of the oven for insuring that the gases entering said second header through a iiue of the iirst named set shall pass froml the header to a flue of the second set having approximately the same location transversely of the oven so las to provide a substantially even distribution of the heat throughout the baking chamber.

JOHN V. COOK. 

